


Trembling sweetness

by heyhay13



Category: Frozen (2013), How to Train Your Dragon (2010), Rise of the Guardians (2012)
Genre: Frozen Universe, Gen, Human Jack Frost, Jack and Elsa as siblings
Language: English
Status: In-Progress
Published: 2014-05-07
Updated: 2014-06-30
Packaged: 2018-01-23 21:08:05
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 4,458
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1579592
Author URL: https://archiveofourown.org/users/heyhay13/pseuds/heyhay13
Summary: <blockquote class="userstuff">
              <p>Jack Frost is Elsa's younger brother instead of Ana. What will they do after the death of their parents?</p>
            </blockquote>





	1. Please

**Author's Note:**

> Some quick info: This takes place after their parents deaths, but both of them are older than in Frozen. Elsa is about 18 and Jack is around 17 =)

_Knock Knock_      

“Elsa…” a rough voice said softly, “Please… I know you’re in there…” it added, cracking a little with the hopelessness and sadness in that voice. Brown eyes looked up at the white and blue door, waiting for a response but there wasn’t a single sound from the other side of the wooden frame. With a sigh that sounded almost more like a whimper the boy turned away, stuffing his hands in his pockets as he went down the hall. The castle was dark and quiet as the kingdom was in grieving over the loss of the king and queen. The young prince was uninterrupted as he meandered as much of the very small staff they had was still cleaning up after the funeral.

As he passed his room he picked up the wooden staff he had left leaning against the door. Feeling over the smooth wood he continued down the dim halls in silence. It was cold but it didn’t really bother him as he went barefoot down the hall. They never had guests so it didn’t matter much that he never dressed as a prince should. He came to the hall leading to the room that had been his parents and he paused at the family portrait hanging on the wall. Looking over it his heart ached as he looked up at the faces of his parents. Beside his father, was him, looking similar to the two of them with his dark brown hair. His older sister stood out with her pale blonde locks and icy blue eyes. The painting of the portrait was actually one of the last times he had seen his sister for longer than brief moments. He sighed, wrapping both hands around the staff as he glanced down the hall back towards his sister’s room. Swallowing hard he started to walk back, knowing he had to coax Elsa from her room somehow.

Once he faced the white door again his voice caught in his throat. He could hear the smallest sound of sniffling from the other side. It gave him a bit of hope as he realized that at least she was actually in there. After a few seconds he actually reached out and knocked again.

“Elsa, I know you’re upset but Arendalle needs you” he said “ _I need you…”_ he added silently but didn’t say it. “You’re old enough to be queen so they expect… well they expect you to step up… they’re already planning the coronation…” He told her. Well, he hoped he was telling her. Currently he was just telling the door, but he quickly perked up at the sound of shuffling on the other side.

“Jack… just… go away...” a broken voice said and he stared blankly at the white wood in front of him.

“ _Ignores me for this long and all she has to say is go away?!”_ Jack thought bitterly, gripping the staff tighter as he calmed down.

“Fine, but they’ll just be back to bother you about it later. Just thought I’d let you know _my queen_ ” He hissed at the door then turned sharply and walked away again, agitated and frustrated at his sister’s stubbornness. Well if she didn’t want his help then he was more than happy to leave her to her own issues. Clearly she didn’t need his help anyways. He looked up, seeing the snow out the window and it brought a small smile to his face. Placing a hand on the glass he could feel the coldness of the ice-like surface. The snow brought back memories of Elsa and him playing as children, but he quickly banished the thoughts as it just brought back the annoyance with his sister.

Back down the hall the white door opened a little right after he had left. Elsa looked out, disappointed to see he wasn’t standing there anymore but he didn’t really blame him. Becoming queen terrified her and now that Jack had come to tell her, to try and help her, it was becoming a reality. She didn’t know what to do but that wasn’t his fault… none of this was ever his fault…

“Jack…” 


	2. Duty

**Summary for the Chapter:**

> The day of the coronation does not bring happiness to this kingdom

The day of the coronation came as a joy to everyone except the two young royals. Several months had passed since the funeral but castle’s emptiness still loomed.

“Prince Jack? My lord are you awake?” a knock from one of the maids came at his door. He swung it open and smiled.

“Of course,” he said but she had an irritated expression. “What? What’d I say?”

“My lord, pardon me, but you cannot go to your sister’s coronation dressed like that!” She snapped and him. He looked down at the blue jacket and brown pants he had on.

“Aww come on, my fancy clothes don’t even fit anymore!” he protested.

“Well we’ll just have to find you new ones! Stay there and I shall fetch a dresser and new clothes,” the woman said then turned off down the hall. Jack grimaced but he had guessed this would happen. Wandering back into his room, he went over to the window and looked down at the crowds gathering outside the gates. The idea of that many people made him both nervous and excited. He had been alone for so many years now that he was desperate for someone, anyone, to notice him. At the same time Jack was nervous that he wouldn’t be able to interact with them anymore. He had such little contact with people that he wasn’t really sure how to act around them now. A knock broke his thoughts and he turned away from the crowds.

“Come in…”

                Jack kept messing with his clothes, constantly adjusting and fidgeting in it. The black suit didn’t fit perfectly as it had been his father’s, but it was better than the too small clothes he had in his room. The castle was alive and bustling for the first time in forever as maids and servants rushed around with final preparations. He avoided running into them as he walked down towards Elsa’s room again, feeling awkward without his staff or normal clothes. When he got to her room though, he was surprised to see it open already.

                “Um… Hello? Elsa…?” He said, nudging it open a little more as he looked inside. Empty. Well then.

                Turning out of the room he shut the door and spotted a passing maid.

                “Hey, have you seen my sis-um, Princess Elsa?” he asked and the woman nodded.

                “I believe she was in the throne room, my lord.” the young lady said before continuing off down the hall. Jack was a little surprised but he decided to try and find her, especially if she was actually outside of her room.

                When he reached the throne room, he was a little surprised to see that she was, in fact, inside. The future queen stood in front of a portrait of their father from his coronation as king. In her had was a candle and sphere that looked similar to the scepter and orb she would have to hold during the coronation. He let out a small cough and she whirled around, dropping the two object on the floor with a loud clatter.

                “Oh! Um… hi, Jack.” she said, relieved that it was just her brother but she had a small blush of embarrassment over her cheeks. He leaned down and picked up the things she had dropped, a little surprised at how cold they were.

                “Didn’t think you were the nervous type,” he said, setting them back on a table then turned back to her.

                “Well… I just, um, don’t want to make a mistake,” she lied quickly but Jack could see the fear in her eyes.

                “You’ll do fine Elsa,” he said with one of his trademark smiles but Elsa had turned back to the portrait. Her icy blue eyes stared up at the painting.

                “Jack… I’m scared…” she whispered softly and his eyes widened.

                “What? Aw come on, you’ll be great!” He encouraged. “We just need to calm you down… I know, we could play a game!”

                “Jack this isn’t a joke! I-I-I don’t think I can do this!” Elsa snapped, turning to face him with a look of desperation and terror.

                “What? But Elsa, Arendalle needs you! You’re becoming queen today! You have to! There’s no one else that can do this!” He argued and Elsa paused. She glanced at the portrait then back at him. In their father’s clothes, Jack looked remarkably like him.

                “You could…” She muttered then looked at him with wide eyes. “That’s it! You can do it Jack! You can become the king and lead them, you can do it!” She said quickly. He stepped back, completely stunned.

                “What?! I can’t! I-I don’t even look like a king Elsa! I hardly want to be a prince, how could I be king?!” He snarled at her, clear that both of them were panicked now.

                “Jack you might not have the training, but your heart is pure. I know you could do Arendalle well.” Elsa said, pleading with him.

                Before he could reply there was a knock at the door. The siblings looked to the door then at each other.

                “Princess Elsa?” the butler asked from the other side of the door. “My lady, it is time.”

                “Jack-?”

                “NO! Elsa I can’t!!” he shouted at her, “You have to do this, it’s your job!”

                “B-But I can’t conceal…D-Don’t feel…”Elsa muttered to herself now. “It’s too dangerous…”

                “What?” He said but the door opened up.

                “My lady?” the butler said as he saw Jack and Elsa both inside.

                “No.” Elsa said, suddenly looking back up at them then looked directly to their butler. “Jack shall become the king of Arendalle.”

                “Princess-?” He questioned in alarm.

                “Enough! It has been decided!” She snapped and pushed past the two males and stormed down the hall.

                “ELSA!” Jack shouted and raced after her, following the sight of her magenta cape disappearing around corners and down the halls. He didn’t notice the odd frost on the floors and creeping up the walls as he ran after his sister, catching up to her in the room where her coronation was to take place. The crowd of people gathered to watch were already looking up at the to-be queen.

                “There has been a change in events. I apologize greatly, but my brother Jackson shall be the one to take the throne. He will be crowned today instead of myself.” She started, instantly creating an uproar of whispers and chattering in the audience. Jack threw the doors open, stunning them back into silence as he walked in. Elsa gave him a threatening glare to try and make him back down and keep quiet, but it was far too late for that.

                “NO! Elsa you cannot just dump **your** responsibility just because you can’t get over our parents’ death! They’re _gone,_ so get over it!” He snarled. The tension in the room was nearly palpable as the siblings stared each other down. “Who ever said I _wanted_ to be king?! To give orders and try and rule a country?! No! That’s not for me! Elsa this is **your** duty!” Jack snapped, reaching out as Elsa turned to likely run away again. She jerked back and, to her horror, realized the teal glove on her hand had come off in Jack’s grip.

                “Enough Jack! G-give it back!” She yelped quickly but he wasn’t paying attention.

                “Mom and dad’s death hurt me too Elsa!” He said, his tone shifting as he looked her in the eyes. “But you weren’t there either! It was like you died right along with them!”

                “I said **ENOUGH!** ” Elsa snapped, followed by an explosive sound that stunned everyone. White magic shot from her exposed hand and Jack jerked back as a row of razor sharp icicles lined the floor. His eyes widened and he looked up at her in shock.

                “E-Elsa…?” Jack muttered as it started to make since why she seemed so afraid. His tawny eyes looked up from the ice shards to his sister but she was gone, her cape vanishing behind the closing door.

                “Wait! Elsa!” He shouted and quickly leapt over the ice as the room broke into panicked whispers and accusing shouts of witchcraft. Jack ignored all of them to follow her but she was fast and the icy trail she was leaving behind sent Jack sliding around every turn. When he reached one of the outer doors he thought he’d caught her as it only lead out to the lake but when he threw open the door he saw a bright trail of glowing blue ice expanding over the lake.

                “ELSA!” He called again, hardly hesitating to run across the forming ice. Behind him he could hear the guards running after him, calling for Elsa and him to stop. When they saw him running out over the ice the head guard shouted at the prince to stop, worried that the ice won’t hold. He was right, but Jack didn’t see the white stress lines forming where he stepped until a bone-chilling _CRACK_ rang out and the young prince didn’t even have time to scream before he disappeared into the cold, black waters of the lake. 

**Notes for the Chapter:**

> Okay it followed the video a little more than expected, but now that the basic conflict is set up we're ready to get to the good stuff!


	3. Awakening

**Summary for the Chapter:**

> Jack wakes up to a surprising savior

Jack woke up slowly, shivering a little as he sat up.

                “Elsa…?” he muttered softly, rubbing his head.

                “Prince Jackson! You’re awake!” He quickly looked up at the voice, seeing another young man standing above him. He had jet black hair and hazel eyes that nearly looked golden. The man was in a formal black suit embroidered in silver.

                “Who…?” Jack asked as he looked around. He was back in the palace, back in his room with a roaring fire crackling in the fireplace.

                “General Kozmotis Pitcher, or Pitch if you prefer. I… I pulled you out of the lake Prince Jackson” the man said, looking over him with concern.

                “Just… Jack.” He said as he looked up to Pitch.

                “Alright… Prince Jack then. Are you sure you are alright my lord?” he asked him as the prince got up, tossing the blankets aside.

                “I’m fine. Where is Elsa?” Jack asked quickly.

                “Um… No one has seen the queen in several days.” He replied and Jack spun around.

                “Days?! How long was I asleep for?!” He snapped

                “About four… you were recovering from nearly drowning” Pitch said, worried the Prince would hurt himself.

                “I-I have to go find her!” Jack said, moving to the door and started rushing down the hall.

                “What? No! She’s dangerous! My Prince, she set off an eternal winter!” he said, running after the boy then grabbed his shoulder to stop him.

                “She’s my sister. She’d never hurt me! Now let go!” He snapped, pulling free then continued to walk to the front of the palace Pitch trailed behind him, still trying to talk him out of it but was being ignored.

                “Fetch my horse!” Jack ordered the butler, as he grabbed his hoodie and staff. He pulled the jacket on and walked out, gathering the attention of the townspeople to see the prince out, including that of many of the visiting lords. One approached and Jack remembered his name was Aster Bunny… or something along those lines.

                “Prince Jack, seriously! What do you know about stopping this winter?! You cannot do this to Arendelle!” Bunnymund snapped, having overheard Pitch telling him not to go searching for the queen.

                “What do you know about my sister?! Now I’m going after Elsa!” Jack snapped then mounted the snow white stallion they brought up. He turned the horse to the front gate, glancing back at them. “I’ll be back… just, um, Pitch could you… like, watch over Arendelle for me? Just… like, make sure no one freezes to death or anything, okay?” He asked, looking down at the general.

                Pitch wanted to protest him leaving, but the sincerity in the prince’s voice made him swallow his words. “Alright, I promise to keep them safe.”

                “Thanks.” Jack said, then they watched as he sped off towards the mountains.


	4. Savior

**Summary for the Chapter:**

> Jack sets out to find his sister, but the mountains are a dangerous place.

The storm on the mountain got worse and worse the further he went. The wind continued to pick up and the snow was turning more and more to ice.

“ELSA! ELLLLSSSSSSSSAAAAAAAAAA!” Jack called against the howling winds. He clung tightly onto his horse’s mane, shivering hard. He looked up to call out for his sister again when a blur of color zipped past them and his horse reared up in alarm. “Whoa! WHOA!” He said as he desperately tried to hang on. The stallion panicked as it saw what had spooked it; a large grey and brown wolf was moving towards them. Jack swallowed nervously, trying to figure out what to do when one of the creatures lunged. The horse jerked as it turned and kicked the wolf in the muzzle, sending in flying back but the motion threw Jack off its saddle. The stallion took off, leaping over the creatures and went galloping down the mountain.

“WAIT!!!” Jack shouted, drawing the wolves’ attention to him. He froze as he saw all their eyes turn towards him. He shivered, cold from being dumped in the snow and panicked as the animals padded closer and closer. Standing up he tried to swing at them with his staff.

“S-Stay back!” He shouted, glaring at them. “Get away from me!”

With a snarl, then next wolf leapt at him. Jack swung his staff, hitting it in the side hard enough to deflect the attack, but it moved him closer to the other. He shouted as one snapped at his arm, biting him right below the elbow. Jerking away he was able to dodge another one, but one of them behind him suddenly knocked into his back. The staff slipped from his grip and the heavy animal was pinning him down. He tensed, waiting for it to make the kill and snap his neck when there was a loud howl then the weight holding him down disappeared. Instantly he got the staff then got up, turning to see a sleek black wolf, much larger than the others, fighting the one that had been on him.

“Come on, let’s go!” A new voice called and grabbed Jack’s arm, pulling him towards the forest and then sprinted away from the fight. After a while of running, Jack finally had to stop.

“W-Who even are you??” He panted as he leaned hard on the staff, trying to catch his breath. Jack looked up to his rescuer, surprised that the boy seemed to be his age. He was a brunette, with dark green eyes and freckles dotting his cheeks.

“I’m Hiccup, well, technically it’s Hiccup Horrendous Haddock the third, but Hiccup is kinda bad enough on its own, so yeah… Just Hiccup.” He said, smiling a little, but was blushing when he realized he was babbling. “What about you? What are you doing out here? I mean, other than trying to be dog food.”

                “I’m looking for my sister.” Jack replied

                “Got a name wolf treat?” Hiccup continued to tease.

                “Jack.”

                “Just Jack?”

                “The rest doesn’t matter, I just really need to find my sister. Have you see a girl with really blonde hair out here?” He asked.

                “The only one crazy enough to be out in this storm is you buddy, well, and me.” Jack sighed, disappointed, but got another idea.

                “Wait, do you know what direction the storm is coming from?” He asked

                “Umm…. Well it should be coming from the North, but it’s blowing in from the west, which is weird…” Hiccup said, looking confused. “Why?”

                “The queen set it off. She can do that… apparently.” Jack said.

                “Soooo…. You’re looking for the queen now?” He asked.

                “Well, yes, but-” Jack stopped as he spotted the black wolf behind Hiccup. “Look out!” He shouted, jumping up with his staff ready. The wolf let out a snarl then leapt at them, landing on Hiccup. Jack panicked until he realized that it was licking him, not trying to eat his face off.

                “What…?” He said, standing there dumbfounded a little until Hiccup finally calmed the wolf down enough to sit back up.

                “Jack this is Toothless, Toothless, this is Jack,” the brunette said happily and Jack looked down at the oversized wolf, which looked back at him with bright green eyes.

                “Um… Hi?” The wolf responded with a happy yip and a wagging tail. Hiccup looked back at Jack then glanced at the sky.

                “Well we should probably find some shelter before it gets dark, if the cold doesn’t kill us, those wolves surely might if we’re out here at night.” Hiccup said, standing up.

                “We?” Jack questioned, surprised that Hiccup was still going to help him.

                “I don’t want to freeze any more than you do. Plus if Toothless likes you than I don’t think you could be that bad. I know these mountains a lot better than you do and could probably help you… ya know, um, if you want” the brunette offered, looking over at him.

                “Um… well…” Jack started, still a little shocked. He didn’t like to admit to wanting help, but without his horse he was pretty screwed up here alone. “Thank you…” he said genuinely and Hiccup lit up again.

                “Alright, there’s a trading post just up a little further. It’s a bit of a hike but they’ll have some warmer clothes and stuff for tomorrow” he told Jack then started to lead the way up through the snow. Toothless trotted up after his master, a stark contrast to the white snow as they started walking. Jack paused a moment, noticing he could see most of Arendelle from here. The whole city was covered in a thick layer of white. Turning back to follow Hiccup he silently added;

                “ _Please… for once let me not mess this up...”_

                

**Notes for the Chapter:**

> =3 I'm so excited to be including Hiccup and Toothless in this!!! I hope you like my wolf!Toothless interpretation for the story and let me know what you think so far!!


	5. Adventure

**Summary for the Chapter:**

> Jack and Hiccup head up the mountain.

**Notes for the Chapter:**

> Sorry for the very long wait on this! I've been busy with my For the Fallen Ones fic and the past week has been really awful. My best friend was in a car accident =/ this chapter was kinda a nice happy little break from that.

The trek up the mountain was long and unforgiving as it continued to snow harder the closer they came to the mountain that seemed to be at the center of the storm. The snow piled higher, but Hiccup nor his wolf companion seemed bothered by it. The boy seemed to always be positive even as the storm was beating them down. It confused Jack to know end at why the boy was helping him, especially after having lived his life with little to no contact with the outer world he was growing more thankful for his “guide”.

                After spending the night at the trading post cabin, they had set out that morning. This time, Jack was bundled up in some warmer clothes before heading for the North Mountain. As much as Elsa weighed on his mind though, the young prince couldn’t help at being amazed at all the new things around him and he absolutely adored the snow once he was in proper clothing. He smiled, scooping up a handful of the white powder then nailed Hiccup square in the back of his head. The brunette turned.

                “Now what was that for?” He whined, but was clearly smiling still.

                “Walking is so boring! I wish we could just fly up the mountain,” Jack replied, looking up at the cloudy sky, ignoring Hiccup’s complaint. For a moment, the other boy looked up as well.

                “Well it is worth it right? To find your sister?” Hiccup asked after a moment. Both of them had stopped walking and Jack looked back down at him.

                “Yeah, of course…” he said, then asked “What about you? Do you have any siblings?”

                “No, I used to live with just my father in a kingdom further north… but it just wasn’t really for me I guess.” He said, his hand aimlessly running through Toothless’ fur as he spoke.

                “Why?”

                “Eh… my mother died when I was a baby, and I just don’t think I have ever gotten along with my father. He wanted me to become something I’m not.” Hiccup replied and his words rung very true to Jack.

                “My parents died too… a few years ago. My sister never recovered from it and wanted a similar thing… we used to be so close as children, but something happened and it was like she became scared of me. Losing our parents just made it worse. But I can’t just leave her alone up here. I mean, what if-” Jack started to explain when, to his shock, a ball of snow hit him in the shoulder. He looked up at Hiccup in shock.

                “You were getting way too serious, you need to learn how to have a little fun Jack! Stop worrying, we’ll find her!” Hiccup said with a wide smile and after a moment, Jack chuckled too.

                “ _I_ need to learn how to have fun? I think you need to learn how to make a proper snowball! That was pathetic!” he mocked as he scooped up more snow. Hiccup turned and made a run for it up the mountain side as Jack started pelting him with snow. Toothless ran around the two of them, barking happily and trying to catch snowballs out of the air as Hiccup tried to fire back without much success.

                The boys hardly even realized where they were going as they tried to hit each other until they came around a bend and suddenly Toothless stopped. Hiccup tripped right over the wolf’s back and landed roughly in the snow.

                “Toothless! What’s wrong with you?” He said after he stopped laughing, then followed the wolf’s green eyes to what was towering above them now. To both of their shock, a palace of pure ice stood glittering in the evening sun, reflecting all sorts of colors across the snow. After several moments, Hiccup finally spoke.

                “Think your sister may have gone in there…?” he asked softly. Jack swallowed hard, remembering the ice magic Elsa had released and he slowly nodded.

                “I think this is the place…” the prince said as he walked up to the crystal-like steps that lead to the front doors. He looked back at Hiccup, who gave him an encouraging smile and followed close behind as Jack nervously stepped onto the ice. Fear caused his heart to pound as he remembered her ice shattering under his feet and sending him into the watery depths. Now below them was a deep canyon, but Jack hurried across to the grand doorway.

                “Now what…?” Jack breathed as they stood just a step away. A step away from Elsa, and a step away from finally getting some answers.

                “Well… you should probably just knock.” Hiccup replied, then watched as he reached out a slightly shaky fist to knock on the frozen doors.

                And for the first time in forever, they actually opened up.

**Author's Note:**

> If you didn't notice it or haven't seen it, this fic is based off the Jack & Elsa - Frost Killing Hour: A Family Tragedy youtube video: https://www.youtube.com/watch?v=1mQSPYDc2aY 
> 
> By based off I mean based off! Jack is Elsa's brother but it won't really follow the rest of the video =)


End file.
